﻿<p><em>IfcConversionBasedUnitWithOffset</em> is a unit which is converted from another unit by applying a conversion factor and an offset.</p>

<blockquote class="history">
HISTORY&nbsp; New entity in IFC4.
</blockquote>

<p>Example: The temperature unit Fahrenheit is based on the temperature unit Kelvin as follows:</p>

<blockquote><em>f</em>&nbsp;=&nbsp;<em>k</em>&nbsp;&middot;&nbsp;1.8&nbsp;&ndash;&nbsp;459.67</blockquote>

<p>wherein <em>k</em> is an absolute temperature expressed in Kelvin and <em>f</em> is the same temperature in Fahrenheit.  The following entity instances provide Fahrenheit as a unit:</p>

<blockquote><code>
IfcConversionBasedUnitWithOffset(<br>
&nbsp;&nbsp;&nbsp;&nbsp;IfcDimensionalExponents(0, 0, 0, 0, 1, 0, 0),<br>
&nbsp;&nbsp;&nbsp;&nbsp;THERMODYNAMICTEMPERATUREUNIT,<br>
&nbsp;&nbsp;&nbsp;&nbsp;'Fahrenheit',<br>
&nbsp;&nbsp;&nbsp;&nbsp;IfcMeasureWithUnit(<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;IfcThermodynamicTemperatureMeasure(1.8),<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;IfcSiUnit(THERMODYNAMICTEMPERATUREUNIT, ?, KELVIN)),<br>
&nbsp;&nbsp;&nbsp;&nbsp;-459.67);
</code></blockquote>
